Chinese authorities warned that cyanide levels in the waters around the Tianjin Port explosion site had risen to as much as 277 times acceptable levels although they declared that the city’s drinking water was safe.

Rescuers clear the blast zone in Tianjin Thursday

The local government, under pressure from China’s leaders in Beijing to improve industrial safety, also said it would relocate chemical plants away from the area, where thousands of residents were forced to evacuate last week after the release of toxic chemicals by explosions that killed 114 people.

China’s ruling Politburo Standing Committee called on all levels of governments during a special meeting Thursday to do more to implement and monitor industrial safety rules, the official Xinhua news agency reported.

“Recently, there’s been a series of serious accidents in certain places, once again exposing grave safety risks,” Xinhua quoted from the meeting, which was called by President Xi Jinping to address the Tianjin explosions.

A report from the Tianjin Environmental Protection Bureau issued Wednesday said the tests conducted the day before showed that cyanide levels in the river, sea and waste water in the evacuated area around the explosion site had risen sharply since the deadly blasts.

One testing site at the mouth of a rain water pipe recorded cyanide levels 277 times above acceptable standards.

Drinking water in Tianjin, however, met national standards, according to a separate statement from health authorities on Tuesday.

The government has confirmed there were about 700 tonnes of the deadly chemical sodium cyanide in the warehouse that blew up late last Wednesday.

Tianjin, the world’s 10th-busiest port, will relocate chemical plants from the Tianjin Binhai New Area where the blasts occurred to the Nangang Industrial Zone, 25 km (15.5 miles) away, according to the official China Daily, citing Tianjin Mayor Huang Xingguo.

‘Fish deaths not due to cyanide’

No toxic levels of cyanide have been detected in water samples taken from a Tianjin river where a large number of dead fish were spotted after last week’s explosions.

The analysis was conducted around 5.30pm Thursday at a section of the Haihe River, which is several kilometers away from the site of the explosions at the north China port, according to the city’s environment monitoring center.

Responding to questions on the death of the fish at a press conference at 4 pm, Deng Xiaowen, the center’s head, said an investigation would be launched but assured that it was not uncommon for fish to die en masse in local rivers during summer, due to poor water quality.